The invention relates to a method according to the preamble of claim 1.
A method of the generic type is known from EP 0 124 211 B2. In this case, a workpiece is shifted between two adjacent stitches by a greater length than another workpiece. To this end, control data of a sequence or a profile of varying feeds and advances is given by a control unit in dependence on a count of a stitch counter. A similar method is known from the PFAFF leaflet 3834-4/11.
DE 34 90 775 C2 (corresponding to WO 86/02673) teaches a fundamentally similar apparatus.
It is an object of the invention to embody a method of the generic type such that programming the sewing machine can be carried out very easily and without too much time needed.
According to the invention, this object is attained by the features of the characterizing part of claim 1. The gist of the invention resides in that the lengths of sections that have been determined by the modeler are directly fed in. No stitch counts are fed in for certain stitch lengths, but the desired stitch length in addition to the length of the individual sections. Based thereon, the computer determines gathering values, which are displayed on the display unit of the operating and control system, thus being visible and verifiable for the operator. If necessary, the gathering values may be modified by the operator if the sewing pattern does not correspond to the predetermined values. The computer automatically considers such a modification of the gathering values in correspondingly triggering the feeder-actuating stepper motors. A modification of the desired stitch length does not affect the values determined for the individual sections. Correspondingly, the operator is free to suit the stitch length to fabric quality or to select them in accordance with fabric quality. Corresponding to the given stitch length, the computer automatically determines the triggering data for the stepper motors.
The input, according to claim 2, of graduation values given by the modeler for the sections of a basic garment size enables values to be prepared automatically for the workpiece sections of other garment sizes, there being no need for any time-consuming input of values for workpieces of other garment sizes.
As a result of the input of so-called fabric correction values according to claim 3, the effect of the advance motion of the respective feeder on the workpiece it transports is taken into account. This is important in particular for very smooth fabrics, in which case slip will occur between the fabrics and the feeder. It may be equally important for very rigid or thick fabrics.